Open AccessStudy of the influencing factors of the liquid CO2 phase change fracturing effect in coal seams
Author(s) -
Jinzhang Jia,
Dongming Wang,
Bin Li,
Tian Xiuyuan
Publication year - 2021
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0254996
Subject(s) - materials science , cracking , coal , coal mining , ultimate tensile strength , elastic modulus , fracture mechanics , radius , modulus , compressive strength , geotechnical engineering , composite material , geology , chemistry , computer security , computer science , organic chemistry
To study the influence of different factors on the cracking effect of the liquid CO 2 phase transition, the mechanics of coal rock crack extension based on liquid CO 2 phase change blast loading were studied. Through the application of simulation software to analyze the influence of coal seam physical parameters (in situ stress, gas pressure, modulus of elasticity and strength of coal) and blasting parameters (fracturing pore size and peak pressure of detonation)on the effect of liquid CO 2 phase change cracking, the simulation results showed that the cracking effect of liquid CO 2 phase change was positively correlated with the changes in gas pressure, elastic modulus, fracture hole diameter and peak vent pressure, negatively correlated with the variation in situ stress and compressive strength, and nearly independent of the tensile strength. In addition, by using Gray correlation analysis to analyze the influence degree of six main factors on the cracking effect, the calculation results showed that the effect of blasting parameters was greater than that of physical parameters. The main controlling factor that affected the blasting effect was the peak pressure of blasting release. By conducting comparative engineering trials with different blasting parameters, the test results showed that the crack effect of the coal seam was positively correlated with the change in fracture hole diameter and peak venting pressure, which was consistent with the results obtained from the simulation. The experimental results and simulation results for the effective radius of coal seam fracturing were basically consistent, with the error between the two types of results falling below 10%. Therefore, the reliability of the blasting numerical model was verified. In summary, the research results provide theoretical guidance for applying and promoting liquid CO 2 fracturing technology in coal mines.